"Right at this moment, till the water recedes, people need emergency relief, like food, medicine, water purifying tablets and things like that, and maybe clothes," he said.

"But very shortly, there'll be a massive need for reconstruction materials, you need an enormous amount of money for reconstruction of communication systems, the damaged houses of people, the schools and so on and so forth."

While the weather in some northern parts of the country was set to improve, more rain is forecast for the central region - including Dhaka.

"I have nowhere to go. Allah seems to be unkind to me,"
Safura Begum, a 35-year-old mother living on a Dhaka pavement with her young children, told Reuters news agency.

Tempers flare

Fifteen people were wounded in Dhaka when police opened fire to break up a fight between residents, Reuters said.

The clash happened when people in one quarter opened a sluice gate to ease flood pressure in their neighbourhood - only to inundate another.

In India, 460 people were reported to have died in Bihar state to the west of Bangladesh. Flood waters were reported to be receding.

A reported 181 people have died in the neighbouring Indian state of Assam - many from waterborne diseases, said the state health minister.

He said emergency provisions of barley and biscuits had been ordered to help thousands of infants suffering malnutrition.